You’re probably already aware of the ubiquitous blue bubble solar pool blanket on someone’s pool. Maybe even on your own pool already. Do solar pool covers work and are they worth investing the money to buy one?
If you’re ok taking a few extra minutes each night to put a solar pool cover over your pool, you might be pleasantly surprised at the benefits.
Do Solar Pool Covers Work?
Yes, solar blankets work and they actually do a few other things as well.
Solar Blankets Retain Heat
One study in Michigan found that a middle school pool reduced energy costs by 55% after they started using a pool cover. The solar blanket retains the heat in a pool especially overnight when the sun is down and the cooler temperatures kick in.
But solar blankets can also be used during the day when the sun is up. While you don’t want to leave a solar blanket on the pool for days at a time – that can encourage algae growth – leaving the blanket on during the day will help to retain more heat on a hot day.
Solar Blankets Create Heat
Solar blankets do more than just retain heat. In fact, solar blankets also take the heat from the sun and transfers it to the pool water. While an open pool can reflect sun rays, the material of solar blankets is designed to take the heat from the sun and pass it onto the water effectively helping to heat the pool rather than simply retaining the heat that pool already has.
We’ll discuss more on that in a moment…
Solar Blankets Reduce Chemical Usage
The same Michigan study quoted above also found that after they started using the pool cover, the evaporation of water dropped which in addition to saving on water costs to refill the pool, also decreased the use of chemicals. While they used to add chemicals to the pool every week, now they add chemicals every 10 days. This may be a chlorine pool but the reduced evaporation will save even a salt water pool owner money and time in the long run.
And this Michigan pool is an indoor pool so they additionally discovered that humidity was reduced when the solar blanket was used. An outdoor pool will undoubtedly experience more evaporated water from direct sunlight that a solar blanket may help to prevent.
A 2016 California study compared 7 pool covers including solar blankets (referred to as bubble cover) as part of a greater project to reduce urban water usage by 25%. They discovered the following:
Solid track cover, foam cover, and bubble cover reduced evaporation by about 95 percent.National Plasterers Council
So a typical solar blanket (bubble cover) may reduce the evaporation of water in a pool by about 95%.
As an FYI, liquid products that are added to the pool and sit on the top of the water to protect it from UV and sunlight didn’t fare very well in the study.
Solar Blankets Lowers Maintenance Time
Given that it covers the entire pool, a solar blanket additionally prevents leaves and other debris from falling in the pool which can decrease your maintenance time and costs over time.
It also helps to keep the skimmer and pump basket cleaner which ensures that water flow isn’t negatively affected by blockages.
You may find that as a result of leaves falling onto the pool cover though, they often dry and need to be rinsed off the pool cover which can get a bit grubby at times as a result.
Solar Blankets Save Lives
I can speak from personal experience. While I have unfortunately fished drowned mice and chipmunks out of the pool – and also rescued a few live frogs who were floating around the skimmer and couldn’t get out – the solar blanket does help to increase the chance that frogs, mice and other small rodents don’t fall in and drown.
While it certainly won’t save a human or even a cat or dog, smaller animals can often hop back out of the pool after landing on the pool cover accidentally. Not only does it help to save their lives but also prevents you from having to fish a rotting dead animal from the pool or skimmer.
How Does A Solar Blanket Work?
The heat from the sun hits the blanket and warms it up and that heat is then transferred to the water. So in addition to keeping the warmth of the pool, the solar cover actually helps create heat additionally.
A typical solar pool blanket effectively forms a vapor barrier over the pool to keep heat in and retain moisture, too ie. it lowers evaporation.
Why are pool covers blue? The truth is that while the old school ones we typically see are blue, they come in several other colors too.
You typically see a medium blue color for most pool covers. This is because this blue shade does a good job of trapping heat while also helping to block UV rays which protects the chemicals in the pool. Chemicals including salt-generated chlorine gets killed off by direct sunlight but the pool cover can help to shield water from harmful UV rays.
Clear pool covers exist and they tend to be better at allowing more heat into the pool possibly heating the pool more than the blue cover. The trade off is that UV rays tend to penetrate the clear cover which can damage the chemicals in the pool.
Dark blue pool covers also exist. This color tends to be the best color for heat gain and heat retention at night. The net heat gain with a dark blue cover is less than a clear one however.
You may also come across tan and gray pool covers that tend to retain their color and hide dirt better than say a clear pool cover.
So why is the medium blue color the one you tend to see? It’s the one that offers benefits both at night when people tend to use the pool cover and also during the day when there is direct sunlight too.
- Solar pool covers offer several important benefits to pool owners namely heat retention, heat creation, evaporation protection and some protection for small animals who may accidentally fall into the pool, among others.
- Solar blankets may also protect your water against UV rays – depending on what color you choose as mentioned above – which additionally protects the chemicals in your pool helping them last longer.
- Check out this other post I wrote called 5 Ways To Save Money On Your Salt Water Pool which discusses not only solar pool covers but solar cover rollers, pool heaters and other devices that may (or may not) benefit your pool.